Bug fix for SQL error "Duplicate entry 'xxx' for key 'PRIMARY'

As I understand, this file should be a update file and therefore not set primary keys nor try to re-insert the existing content types. Tested with J3.0.3 to J3.1.1 update.
PLEASE NOTE:
I don't have the possibility to test the postgresql and sqlazure versions and therefore I didn't change them, but I think they should also be changed.

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